Yeast Fermentation Lab

Topic Question: How does the amount of sugar affect the rate of fermentation?

Experiment: Materials: package of dry active yeast ruler or meter stick 250 mL beaker string 250 mL flask balloon sugar packets warm water (110 ºF)

Procedure: 1) Fill the beaker with 100 mL of warm tap water. 2) Add 1 package of yeast to the warm water and stir until it is in solution. 3) Carefully pour the yeast solution into the flask. 4) Complete the lab according to the group you have been assigned.

Group 1: After pouring your yeast solution into the flask, immediately place the balloon on the top of the flask. Note the time on your lab chart.

Group 2: After pouring your yeast solution into the bottle, add 1 packet of sugar to the mixture and swirl it gently until it dissolves. Then place the balloon on top of the bottle. Note the time on your lab chart.

Group 3: After pouring your yeast solution into the bottle, add 2 packets of sugar to the mixture and swirl it gently until it dissolves. Then place the balloon on top of the bottle. Note the time on your lab chart.

5) Using your string, measure the size of your balloon every 5 minutes. Record the information on your data table. Name: ______Yeast Fermentation Lab

Hypothesis:

Experiment: Illustrate how you set up your experiment. Be sure to label the parts.

Results: Data Chart:

Amount of Time Start 5 min 10 min 15 min 20 min 25 min Group 1 2 3 4 5 6

Graph:

1. What was the manipulated or independent variable in this experiment? 2. What was the dependent or responding variable in this experiment? 3. Which one of the groups was the control? Why was it the control?

On the graph paper provided, create a multi-line graph to show your data. Conclusion:

4. Which of the balloons reached the largest size?

5. What material was collected in the balloons?

6. What is fermentation?

7. What are the products of fermentation?

8. What caused the balloons to increase in size?

9. What does the information from your graph tell?

Analysis: 10. Yeast is used in making bread. Using the information obtained in this experiment, explain what causes bread to rise and what conditions are necessary for optimum rising?